4 Answers
4

Without hassle, use 1/4 as-is, or $\frac{1}{4}$ (similar to amsmath's \tfrac{1}{4}) will typeset one quarter. If you want to add " in order to represent "inches", you could use $\frac{1}{4}''$, which is equivalent to $\frac{1}{4}^{\prime\prime}$. xfrac also produce so-called "vulgar fractions" via \sfrac{<num>}{<denom>}. Here are some examples:

Note that there might be some spacing issues if you use two "text fractions" in successive lines, since the ascenders and descenders of the respective lines push them further apart (lines 1-3 exhibit this stretched look). As such, the "vulgar fractions" are sometimes preferred, since they take up less vertical real estate.

I don't understand the context of your question. LaTeX provides the much overused $\frac{1}{4}$ but this has several disadvantages, especially if it's used in ordinary math mode (as part of the running text). First, it changes the size of the figures in the numerators and denominators, and second it may screw up the interline spacing. If you just want to write something simple stating that y is a quarter of x then I suggest you write $y=x/4$. Writing this is easier on the eye than $y=\frac{1}{4} x$. For more complex statements, writing $4 y = x$ or (better?) $x = 4 y$ may look better than $y=\frac{1}{4} x$.